Systems and methods for wound healing

ABSTRACT

Systems and methods can promote wound healing, including a wound dressing having a wound-facing surface and a second surface. The wound-facing surface can be configured to contact a wound of a patient. There can also be at least one conduit having an interior lumen operably connectable to the second surface of the wound dressing, a central window configured to allow air flow from the interior lumen of the conduit to the wound-facing surface of the wound dressing, and a flexible wrap operably connectable to the conduit.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims the benefit under 35 U.S.C. § 119(e) as anonprovisional application of U.S. Provisional Pat. App. No. 62/006,755filed on Jun. 2, 2014 which is hereby incorporated by reference in itsentirety.

BACKGROUND Field of the Invention

The invention relates to, in some aspects, systems and methods for woundhealing.

Description of the Related Art

Research has established that wound complications among overweight andobese women are higher compared to non-obese mothers. The AmericanCollege of Obstetricians and Gynecologists (ACOG) released an officialCommittee Opinion in January 2013 stating, “Obese women who requirecesarean delivery have an increased incidence of wound breakdown andinfection.” Conner et. al. presented a poster at the 2013 Society ofMaternal Fetal Medicine that showed a 10.9% versus 6.6% incidence ofwound complication for obese versus non-obese women.

Nationwide, there were approximately 727,000 cesarean deliveries byoverweight and obese mothers in 2010. Considering an infection rate of10% and a current cost between $3,382 to $10,443 per patient, the excesshealthcare spending on this addressable problem is between $246M and$759M per year in the US. Additionally, because infection-relatedreadmissions are now subject to reimbursement penalties hospitals areincreasingly responsible for those costs.

Despite the latest technologies and improved techniques, surgical siteinfection (“SSI”) following cesarean in overweight and obese womenremains a challenge. While common procedures to reduce wound infectionshave certainly reduced the adverse outcomes, there is room forimprovement. Current strategies which have been in place for severalyears may not go far enough. A new and novel addition is needed.

SUMMARY

Disclosed herein are systems for promoting wound healing. In someembodiments, the systems can include a wound dressing having awound-facing surface and a second surface, the wound-facing surfaceconfigured to contact a wound of a patient; at least one conduit havingan interior lumen, the conduit operably connectable to the secondsurface of the wound dressing, wherein the conduit comprises a centralwindow configured to allow air flow from the interior lumen of theconduit to the wound-facing surface of the wound dressing; and aflexible wrap operably connectable to the conduit.

Also disclosed herein are methods for improving wound healing. Certainmethods can include one or more of the following steps: identifying apatient at risk of wound dehiscence; positioning a wound care systemcomprising a wound dressing having a skin-contacting surface and asecond surface, a conduit having an interior lumen connected to thesecond surface of the wound dressing, and a flexible wrap operablyconnected to the conduit proximate a wound of the patient's skin, andsecuring the wrap around a portion of the patient. The wound dressingcan be positioned substantially co-linearly along a long axis of a woundof the patient's skin. Positioning the wound care system can stablyreposition overhanging skin or adipose tissue surrounding the wound to alocation farther away from the wound.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 illustrates two examples of abdominal surgical incisions.

FIG. 2 illustrates an embodiment of a wound care system 100, including awound dressing, a conduit, and a wrap.

FIG. 3A illustrates an embodiment of a conduit having a sidewall,interior lumens, and closed or open ends.

FIG. 3B illustrates an embodiment of a conduit with a sidewall havingopen areas and trussed regions such as struts.

FIG. 3C illustrates an embodiment of a conduit with a central window.

FIG. 3D illustrates an embodiment of a conduit with a plurality ofcentral apertures.

FIG. 3E illustrates an embodiment of a conduit that includes arestriction within the interior lumen.

FIG. 3F illustrates an embodiment of a conduit that includes sensorsoperably attached to the conduit and adjacent the wound dressing.

FIGS. 4A-4C illustrate various embodiments of cross sections of portionsof wound care systems.

FIG. 5A illustrate an embodiment of a wound care system including aconduit with a plurality of lumens.

FIG. 5B illustrate an embodiment of a wound care system including aconduit with a movable structure.

FIG. 6 schematically illustrates a wound care system repositioningoverhanging tissue proximate a wound.

FIGS. 7A and 7B illustrate perspective views of a wound care systemincluding wound care dressing, conduit, and wrap.

FIGS. 8A-8G illustrate perspective views of embodiments of wound caresystems.

FIG. 9 illustrates schematically the positioning of the devicetransversely across the abdomen,

FIG. 10 illustrates the Bernoulli equation, and the moisture diffusionrelationship derived from Fick's Law, and a schematic showing deviceover the patient's abdomen.

FIG. 11 illustrates a view of device removed from the patient on thetop, and a perspective view of an embodiment of the system on thebottom.

FIG. 12 illustrates from left to right, an embodiment of the systemshowing the lateral snorkel portion of the conduit, the conduit-wounddressing, and the wrap in position on a model patient.

DETAILED DESCRIPTION

In some embodiments, systems and methods disclosed herein can include awound dressing material and an apparatus that provides an optimizedwound healing environment for a wound or surgical incision. Theextensive literature regarding the topic of wound healing and infectioncontrol of surgical incisions discusses the factors which contribute toand promote wound healing. A variety of intrinsic and extrinsic factorscontribute to the timely, successful, and uncomplicated healing process.However, complications may often arise, as in the case of a patient withcomorbidities, localized physiology, and localized morphology, and whichmay result in impaired wound healing and/or infection and/or abscessand/or any of the related complications regarding the aforementionedwound healing challenges.

In some embodiments, systems and methods can temporarily reposition bodytissue surrounding and near a wound and encourage healing of a surgicalor nonsurgical wound. In some embodiments, the systems are applied as amedical device and used by the patient for a period ranging fromimmediately post-surgery to a duration of weeks or beyond, a decisionbest determined by the practicing physician and team responsible for thepatient's care. In some embodiments, systems and methods can provide oneor more of the following: a wound dressing that provides structure totemporarily reposition skin/tissue during healing; adjustable tensionand compression for optimal fit to the body; protects delicate incisionsite during healing; can control the micro environment around theperi-wound area to decrease wound healing complications; allowsotherwise occluded wound site exposure to ambient environment to supportand sustain natural wound healing; manages moisture and exudate from theskin and wound; provide cesarean incision wound healing monitoring andcommunicates status by combining pH, temperature, and relative humidity;and combine an abdominal compression binder with wound dressing padwithout occluding the incision site.

Systems and methods as disclosed herein can, in some embodiments,counteract the often interruptive healing effects of excess andmalpositioned tissue and adipose that can surround the wound andperiwound regions. Excess tissue can complicate and inhibit the woundhealing process when those tissues contact, fold, fold upon, overlay,occlude, abrade, irritate, and impact the incision area, wound bed, itssurrounding area and tissue, and negatively affect the physiological andenvironmental variables associated with optimal wound healing and tissuevitality. Skin flora and other organisms can also potentiallytranslocate into the wound, leading to wound infections. Devices asdisclosed herein can temporarily reposition tissue proximate the woundsuch that it is no longer interfering and affecting the localizedhealing environment.

In some embodiments, systems and methods can incorporate activefeatures, devices, and characteristics to enhance the healingenvironment in a positive aspect, such as controlling the air pressuresand velocities to the wound surface.

The system and apparatus incorporate features and characteristics toenhance the localized healing environment, addressing variables andfactors such as:

-   -   ventilation    -   temperature    -   relative humidity    -   surface moisture    -   acoustics    -   stresses, strains, e.g. shears, contact pressures, and normal        forces (radial forces delivered via hoop stress of the        apparatus)    -   photoactivity    -   microbial activity    -   exudate management

A non-limiting example of a wound in which this system may be used is topromote healing of a transverse incision in the abdominal area, such asone that a patient would receive if delivering a baby via cesareansection. Delivery by cesarean section may involve a variety ofincisional approaches, developed over the years and discussed in theliterature (e.g. Pfannenstiel, ‘bikini’, Joel-Cohen, etc). Typically, anincision is made in a transverse fashion in the lower abdominal area ofthe pregnant mother. The incision may be centered/mirrored symmetricallyabout the sagittal plane, asymmetrical to that plane, or a variation,all of which are discussed in the literature. FIG. 1 illustrates twoexamples of abdominal surgical incisions 101 on a patient's abdomen,including a vertical incision 102 on the left, and a horizontal incision104 on the right, which can be a Pfannenstiel incision commonly used forCaesarean sections. Other non-obstetric related abdominal wounds canalso be treated by systems and methods as described herein, includingabdominal surgical wounds such as bowel resection, adhesionolysis,appendectomy, cholecystectomy, liver resection, Roux-en-Y, and otherprocedures involving an abdominal incision, as well as gunshot, stab andother traumatic wounds, and fistulas. Non-abdominal wounds such as chestor other sternotomy incisions, scalp/cranial, upper extremity, lowerextremity, spinal/back or hip incisions/wounds, or diabetic leg or footulcers for example can also be treated using systems and methods asdescribed herein.

In the case of a pregnant mother of normal, elevated, high, or extremelyhigh (and beyond) body mass index (BMI), who delivers via a cesareansection, there may be complications of wound healing related to thephysical manifestations of tissue in the area of the wound bed and thesurrounding area of the incision site. The surrounding tissue may bepositioned over, adjacent, or against the incision site, resulting in avariety of negative factors such as (any, all, or a combinationthereof):

-   -   occlude the wound and surrounding tissue from exposure to the        environment;    -   not allowing the wound and its dressing to ‘breathe’;    -   create a state of elevated temperature and moisture;    -   result in maceration of surrounding tissues and the wound;    -   encourage growth and proliferation of bacteria and microbes;    -   decrease photoactivity (exposure to light) from the environment;    -   reduce or impair ventilation across and over the wound bed and        surrounding tissues; and    -   affect the skin forces around the wound bed and surround tissue.

In some embodiments, systems and methods can include identifyingpatients at risk for poor wound healing, including patients with a BMIof at least about 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37,38, 39, 40, 41, 42, 43, 44, 45, or more, and applying a system such asthose disclosed herein. In some embodiments, patients at risk for poorwound healing can be identified by the presence of one or more riskfactors for poor wound healing, including but not limited to advancedage, smokers, diabetes, malnourished patients, alcoholism,corticosteroid use, chronic kidney disease, peripheral vascular disease,previous history of poor wound healing, and the like.

In some embodiments, systems and methods as disclosed herein cancounteract the often interruptive healing effects of excess andmalpositioned tissue and adipose that surround the wound and periwoundregions. Excess tissue can complicate and inhibit the wound healingprocess when those tissues contact, fold, fold upon, overlay, occlude,abrade, irritate, and impact the incision area, wound bed, itssurrounding area and tissue, and negatively affect the physiological andenvironmental variables associated with optimal wound healing and tissuevitality. In some embodiments, the system can temporarily reposition thetissue such that it is no longer interfering and affecting the localizedhealing environment.

In some embodiments, wound healing systems can incorporate features,devices, and characteristics to enhance the healing environment in apositive aspect, such as controlling the air pressures and velocities tothe wound surface. For example, in some embodiments, features andcharacteristics of systems to enhance the localized healing environmentcan address variables and factors such as:

-   -   ventilation    -   temperature    -   relative humidity    -   surface moisture    -   acoustics    -   stresses, strains, e.g. shears, contact pressures, and normal        forces (radial forces delivered via hoop stress of the        apparatus)    -   photoactivity    -   microbial activity    -   exudate management

FIG. 2 illustrates an embodiment of a wound care system 100. Wound caresystem 100 can include a wound dressing 200, one, two, or more conduits202, and a wrap 204. The wound dressing 200 can include a wound-facingsurface and a surface opposite the wound-facing surface. Thewound-facing surface of the wound dressing 200 can be configured to restagainst a patient's skin, such as proximate or within the wound. Thesurface opposite the wound-facing surface can be operably attached tothe conduit 202. The conduit 202 can operably be attached to a wrap 204,such as an abdominal binder, ACE wrap, or the like.

The wound dressing 200 can be comprised of a number of dressings, suchas gauze including cotton and Vaseline gauze, hydrocolloids, alginates,hydrophilic polyurethane foams, silver antimicrobials, copper or otherionic antimicrobials, gauze with additional antimicrobial additives,growth factors (including EGF, KGF, IGF, PDFT, TGF, FGF, VEGF, andothers), and foam with and without additives.

The conduit 202 can be configured to temporarily reposition overhangingtissue around the wound bed, creating a direct or indirect conduit tothe ambient or external environment. In some embodiments, the conduit202 can have a generally tubular (e.g., cylindrical) structure with acircular, oval, or other symmetric or asymmetric cross-section. Asillustrated in FIG. 3A, the conduit 202 can have a sidewall 203, one,two, or more interior lumens 205, and closed or open ends 204 (or oneclosed and one open end). In some embodiments, the sidewall 203 can becontinuous, or noncontinuous (such as forming a “C” shaped cross-sectionfor example) and either permeable or non-permeable. In some embodiments,the sidewall 203 of the conduit 202 can have open areas 206 and trussedregions 205 such as struts as illustrated in FIG. 3B. The function ofthe continuous sidewall 203, or trussed regions 205, in someembodiments, is to counteract forces imparted by the tissue which istemporarily repositioned, and to maintain a lumen or conduit to theenvironment that can remain patent during typical motion and activitiesof the user.

In some embodiments, the axial length of the conduit 202 can range fromapproximately 3 inches to approximately 40 inches. The conduit 202 canbe substantially the same length as, or longer than the axial length ofthe wound dressing 200, such as at least about 10%, 20%, 30%, 40%, 50%,75%, 100%, 150%, 200%, 250%, 300%, or more longer than the axial lengthof the wound dressing 200. The diameter of the conduit 202 can vary insome embodiments from about 0.25 inches to about 4 inches in order toaccommodate patients of a variety of shapes and sizes. The radius mayoptionally be non-constant and the cross section may be asymmetric orsymmetric.

The wound care device can be secured in direct contact to the skinsurface on the wearer with, for example, adhesive or in combination witha wrap, such as an abdominal binder. The binder can include anadjustable strap and fastener that allows easy application or removal ofthe device.

In some embodiments, as illustrated in FIG. 3C, one or more windowportions 220 such as a cut-out can be present between the two ends 204of the conduit 202, such as near the center of the conduit 202. This iswhere the wound dressing (not shown for clarity) overlays the wound bedand is in contact with the healing wound. The cutaway window 220 can, insome embodiments, have dimensions of about 3 inches to about 12 inchesin length and a height approximately 1 to 4 inches. The corners andedges of the cutout window may optionally be round, smooth, or radiusedas to improve the interface between the wound care device and the skin.Additionally, in some embodiments, the inner edge of the window 220 caninclude a co-molded or added-on lip or gasket of a soft material, suchas silicone, which provides a gradient transition between the lessflexible, more rigid conduit 202 and the cutaway where the wounddressing overlays the wound bed and surrounding area. The conduit matrixcan also overlay on surrounding tissue areas surrounding the wound bed.

In some embodiments, instead of a window 220, as illustrated in FIG. 3D,a conduit 202 can include a series of apertures 222 to provide a pathfor communication to the wound dressing. The number, size, and spacingof the apertures can vary depending on the desired clinical result. Theapertures can be generally centrally located along the conduit 202 insome embodiments. In some embodiments, rather than discrete aperturesthe zone that would contain the window 220 or the apertures 222 could bemade of a porous material to provide the communication to the wounddressing.

The conduit 202 can include a hollow core or lumen, which contacts thenon-wound-contacting side of the wound dressing, and is bound by theinterior surface, e.g., inner diameter of the conduit 202. The exteriorsurfaces of the conduit 202 can be configured to interface, displace,and/or temporarily move the tissue and adipose surrounding the wound.The interior lumen of the conduit 202 can be left open/hollow, partiallyfilled with additional wound management materials like foams, dressings,and moisture absorbing materials, or completely filled for example by amatching foam core, which may be attached to a mechanized system tomanage wound exudate.

The exterior surfaces, e.g., outer diameter of the conduit 202 mayoptionally include a laminate layer(s) of moisture-absorbing materialsuch as alginate, hydrogels, foams and other hydrophilic materials andcompositions. The function of the moisture management is to absorbexcess sweat and other body fluids and ambient environment which ifpresent may create a sub-optimal wound healing environment.

The interior shape of the lumen of the conduit 202 can be designed suchthat airflow and velocity of passing air currents is optimized to createa Venturi effect. The Venturi effect can lower the local pressure byincreasing the velocity of the fluid passing through a constriction. Inthis example the fluid is ambient or filtered air. Similarly, theinterior lumen of the conduit 202 can enhance airflow across the distalsurface of the dressing. As such, the conduit can include a constrictionregion 226 with a decreased inner diameter akin to the midportion of anhourglass. The constriction region 226 can be proximate or coextensivewith the window/aperture/porous zone of the conduit 202 communicatingwith the wound dressing 200.

In some embodiments, the wound care system can include active componentsrather than being entirely passive. An active conduit 202 couldincorporate one or a plurality of a mechanical valve and sensor assemblyin order to modulate the conditions within the interior surfaces andlumen of the apparatus, accelerative or decelerating moving air currentsbased on the undulations and presence/absence of a pump or fan elementto augment the velocity of air currents.

The flow of air currents within the conduit can provide a coolingeffect, which counteracts the moisture on the skin surfaces and withinthe skin and the temperature increases which result from tissue totissue contact in patients with excess tissue and adipose. The idealtemperature for wound healing is, in some embodiments that of the humanbody's optimal temperature range, such as about 37° C. An optionalconfiguration of the conduit includes the inclusion of sensors which canrecord and communicate the temperature, relative humidity, and/or otherparameters in the wound bed area and surrounding tissue areas. Thesensors can be positioned, for example, in the center, ends, and/orperipheries of the wound area.

In some embodiments, as shown in FIG. 3F, the sensors 224 can beoperably attached to the conduit 202 and adjacent to the wound dressing200 to communicate parameters such as temperature, humidity, and/or pH(e.g., the acidity/alkalinity of the wound bed environment andsurrounding tissue area). The sensor information may be interpreted inorder to understand the local pH of the wound bed and surrounding tissuearea, which may change in the event of a wound infection, for example,empowering the patient and physician to perform earlier stageinterventions (such as starting or changing antibiotic therapy, orperforming a debridement procedure) at potentially a lower cost.

The wound dressing and the conduit can work harmoniously as a temporarysupport and tissue displacement structure and surgical wound dressing tooptimize the acute environment surrounding the healing and care of awound or surgical incision. The wound dressing maintains access to theambient environment via support structures (e.g., the conduit) andreduces exposure to the factors which precede infection and poorrecovery outcomes.

FIGS. 4A-4C illustrate various embodiments of cross sections of portionsof wound care systems. The conduit 202 may compress and deform, but itcan be designed such that it does not fully collapse upon itself. A tubeis one possible embodiment, because the arc and curved surfacesdistribute loads and reduce tendency for the tube to crush. Thecross-sectional profile of the conduit 202 may optionally be a hexagon,septogon, octogon, or any other n-gon, up to circular, where napproximates infinity, as illustrated schematically in FIG. 4B,illustrating the conduit sidewall 203 and cross-section of the lumen205, and also showing wound care dressing 200 operably connected toconduit 202. Alternatively, the luminal cross-section 205 of the conduitcan be asymmetric, as illustrated in FIG. 4A. As illustrated in FIG. 4C,conduit 202 can also include an adhesive layer 206 for temporarilyadhering to the surface of skin surrounding the conduit 202.

In some embodiments, as illustrated in FIG. 5A the conduit 202 may bemade up of a plurality of lumens 202′, such as 2, 3, 4, 5, or morelumens. Each lumen can be in communication with the wound dressing 200,to allow moisture and air to pass from the wound bed to the bandage 200and through the lumens 202′.

In some embodiments, the conduit 202 includes one or more movable partsor structures, such as living joints/hinges, snap joints, fabricatedflexures, heat-shrinked joints or flexures, welded joints, simplemechanical hinges, pinned hinges, flexible hinges, or the like. The typeof movable structure depends on the type of manufacturing. Examples ofdifferent types of manufacturing of the conduit and movable structurescan be blow molding, heat sealing, overmolding, the mechanical assemblyof a rigid paneled chassis with a flexible bladder or skin to form thebody, coining to form living hinges, assembly using gaskets as seals inhinges, injection molding, ultrasonic welding, radio frequency welding,dielectric welding, high frequency welding, dipping, extrusion, spraycoating, brush on, assembly of adhesive backed sheets of variousmaterials, and/or any type of manufacturing that results in a body withpanels that are movable with respect to each other. Movable structures,e.g., hinge 215, is shown in the cross-section of FIG. 5B. The hinge 215can be located distally opposite the incision and may be integrated intothe conduit 202 in any number of ways, such as a co-molded and as amanufactured living hinge 215. The hinge 215 can provide a compressiveforce, in situations where the conduit has a bias to decrease itsdiameter and close. In this optional embodiment, the resulting effect isto unload the periwound area, thereby reducing tension across the woundbed and the incision, which could potentially improve outcomes. Theconduit 202 can act as a longitudinal clip or clamp which reduces theseparation forces across a wound or incision and promotes healing. Thewindow, apertures, or porous material as described above can be utilizedwith this embodiment as well.

In some embodiments, the wound care system can be a combination ofdressing and conduit to make one device, where the wound dressing isinterchangeable, or optionally, it may be supplied as a single-usedevice and the wound dressing and supporting apparatus areinterconnected and not interchangeable.

The conduit can also include other features, including but not limitedto bilateral laterally-extending lumens 309 or “snorkels,” asillustrated in FIGS. 8B-8G below, which may have a smaller, the same, ora larger inner or outer diameter than a lumen of the conduit 202. Onefunction of these snorkels 309 is to interface the conduit 202 to theexterior environment. The snorkel 309, the conduit 202, and theabdominal binder 204 can be conformable such that when applied to apatient they interface with the patient and tissue of the wound bed andsurrounding wound area. The snorkels 309 can exit through a slit orreinforced port in the abdominal binder 204.

If the patient would like to shower with their device, something thatmany wound dressings prohibit, removable end caps can be placed over thelumens and port holes of the conduit. These end caps interface with thecross sectional profiles and areas at the longitudinal ends of theapparatus and when implemented temporarily, contribute a waterresistance which allows the patient to shower or rinse withoutcompromising the wound nor the wound dressing. In some embodiments,rather than end caps, the ends of the conduit can include a valve with acontrol in which the patient can open and close the valve at appropriatetimes, such as before or after washing.

In some embodiments, the device can be worn and applied collinearlyalong the wound or incision line, and positioned underneath overhangingskin or tissue adipose. As shown schematically in FIG. 6, the wound caresystem, including the conduit 202 can temporarily and advantageouslyreposition overhanging tissue 111 around the wound bed 101 such that theadjacent overhanging tissue does not contact the wound bed 101 nor thewound dressing 100, and also advantageously creating a direct orindirect conduit to the ambient or external environment.

FIGS. 7A and 7B illustrate perspective views of a wound care system 700including wound care dressing 200, conduit 202, and wrap 204 asdescribed elsewhere herein. The wrap 204 can include an abdominal binderwith fasteners 227 such as clips or hook-and-loop fastener material, forexample. Also illustrated in FIG. 7B are straps 232 which can be placedover the patient's shoulders, for example for additional support.

FIG. 8A illustrates a perspective view of a conduit 202 with a window222 portion as previously described. Outer surface of the conduit 202can include a connector 204, such as a perimeter of hook-and-loopfastener material to which a wound dressing 200 can removably attach to.Adhesive, clips, snap-on fasteners, and other attachment mechanisms canalso be utilized. The upper portion of FIG. 8B illustrates a tubularconduit 202 with window 220 and lateral snorkel portion 309 aspreviously described. The lower portion of FIG. 8B illustrates a tubularconduit 202 with wound dressing 200 attached along a portion of theouter circumference of the conduit 202.

FIG. 8C illustrates a perspective view of a wound care system includingconduit 202 formed with intersecting struts, lateral snorkels 309 wounddressing 200, and straps 232. FIG. 8D illustrates an end perspectiveview of a device with snorkel 309. FIG. 8E illustrates a close-up viewillustrating the tubular conduit 202 with struts 205, and additionalperi-wound material layer 240 surrounding the conduit 202 and the wounddressing 200. FIG. 8F illustrates another perspective view of thedevice. FIG. 8G illustrates a perspective view of device includingstraps 232.

FIG. 9 illustrates schematically the positioning of the devicetransversely across the abdomen, in this case for a caesarean sectionincision, with straps as part of one embodiment. The straps can beadjustable, and optionally cross in the back, such as a maternitysupport belt. The straps can be configured such that comfort by thewearer is achieved and the device can be utilized for most if not all ofthe day. FIG. 10 also illustrates the Bernoulli equation, and themoisture diffusion relationship derived from Fick's Law, and a schematicshowing device over the patient's abdomen.

FIG. 11 illustrates a view of device removed from the patient on thetop, and a perspective view of an embodiment of the system on thebottom.

FIG. 12 illustrates from left to right, an embodiment of the systemshowing the lateral snorkel portion of the conduit, the conduit-wounddressing, and the wrap in position on a model patient.

Other features of embodiments of wound care systems will now bedisclosed. The system can be comprised of multiple surfaces andmaterials. Medial and lateral to the wound dressing can be surfaceswhich contact the periwound region of the body. This region issusceptible to degradation, breakdown, and maceration resulting frompoor microenvironment management. In some embodiments, for patients whowould be indicated, these medial/lateral surfaces on the posterioraspect of the device (body contacting) have diffusion properties. Thesediffusion properties allow for the passage of liquid and gaseousexchange from the intact, but “sweaty” skin. Thus, they can beabsorbent, lubricious, and/or breathable. Many materials exist todaywhich have these characteristics. Calcium alginates, saline gauzedressings, standard dry dressings, performance breathable fabrics andmulti-laminate fabrics, hydrofibers, hydrocolloids, polyurethanes,celluloses, antimicrobial-enhanced dressings like Medi-Honey or thosewith silver, are all examples of possible materials which may line andcomprise these regions of the device. In some embodiments, the wounddressing or other components can include one or a combination of thefollowing: silk fibers; polyester fibers; nylon fibers; ceramic fibers;polysaccharide fibers including plant fibers such as raw or regenerated(e.g., chemically processed) bamboo, cotton, rayon, linen, ramie, jute,sisal, flax, soybean, com, hemp, and lyocel; animal fibers such as wool;lactide and/or glycolide polymers; lactide/glycolide copolymers;silicate fibers; polyamide fibers; feldspar fibers; zeolite fibers,zeolite-containing fibers; acetate fibers; plant fibers that have beengenetically engineered to express mammalian coagulation proteins ormammalian vasoactive factors. Other fibers that are suitable for use arefibers that have been covalently modified with polymers to promote waterabsorbancy (e.g., polyvinyl alcohols) and polymers that containmolecular moieties that activate hemostatic systems (e.g., linear orcyclized-arginine-glycine-aspartate moieties such as those found ineptifibatide). In some embodiments, materials can include plant fiberssuch as raw or regenerated (e.g., chemically processed) bamboo fibers,cotton fibers, and the like, that have high moisture absorbancy and thatare capable of activating the intrinsic coagulation cascade.

The anterior surface (away from the body) of the medial and lateralregions of the posterior part (body contacting) of the device also canhave unique properties. A combination of microscopic diffusion andmacroscopic diffusion comprise these properties. Macroscopically, theremay be a pattern or an array of passageways which allow bulk liquidtransfer from the body surface to the interior portion of the device andits support matrix. The patterned arrays act as pores or portals forliquid transfer. However, to support moisture transfer in the gaseousstate, the composition of this segment of the device may also havemicroscopic pores, like Gore-Tex or a hydrophilic or hydrophobicsynthetic material—which can be foam and amorphous, a complex woven, ora complex non-woven material. The objective of the material selection isto enhance and optimize the gaseous phase moisture transfer and to allowthe device to modulate the moisture and humidity of the periwoundregion. Combined with the moisture and humidity and temperaturemanagement provided by the device, skin breakdown is avoided and healingand recovery are supported.

Wounds in some cases require a low to no tension environment to heal.The device, through forces applied to the body, relieves tension acrossthe wound. First, through the combination of straps and adhesive, thedevice applies compression to the wound and periwound region.Compression directly over the incision via the conduit and the wounddressing allows for a reduction in tension. The fixation of the devicein its preferred position allows for a low tension environment acrossthe wound and surrounding region.

In some embodiments, the device can be closed or semi-closed to theambient environment. In the closed configuration, the ends of the devicemay be closed or have controlled opening and closure mechanisms. Thepresence of pumps, fans, and valves can control the ingress and egressof atmospheric air. The valves can be positioned somewhere toward theends of the device, however, their location can be anywhere that is notinterfering with their function. The atmospheric air can be conditionedas it flows inside of the interior channel of the matrix supportstructure. With the inclusion of thermal heating elements, resistivewires or a Peltier heat exchange unit, which can be positionedcircumferentially (resistive wires) longitudinally (resistive wires) orat either end or anywhere along the length of the support matrix (bothheat exchanger or resistive elements), the air temperature can bemodulated through a simple control loop.

The atmospheric air can optionally be conditioned by passing over a UVLED or similar electrical element which acts to ionize and decontaminatethe air. In this fashion, the air which is introduced to the wound andperiwound area is devoid of potential microorganisms that can causeinfection to the wound.

In some embodiments, the lumen(s) of the conduit, can have a varyinggeometry to affect the flow velocity and pressure of the atmosphericconditions immediately within the channel. This geometry may allow fornozzles, diffusers, and or parallel channels in which the air flows.

The air is accelerated or decelerated according to the desired localenvironment prescribed by the physician. In an open or semi-openembodiment, a fan or blower may be positioned internal of the channel.This can turn at a constant rate or a specified on/off interval tomodulate the velocity of the air—and correspondingly, the local pressureinternal to the channel.

In a more restricted or entirely closed loop, a pump and valvearrangement can more discretely control the velocity and pressure (canbe held constant by the position and operation of pumps and valves oncea certain pressure is achieved). The pump can be a standard pump thatfits within the confines of the channel, or an advanced active-polymercontrolled by piezoelectrics. The valve may be similarconstruction—electroactive, or a more traditional solenoid or one-waycheck valve.

The humidity can be modulated in part by the absorption and managementof the exudate and moisture produced by the body and the wearer, as wellas it can be conditioned by a moisture pack internal to the channel ofthe support structure.

The device support (e.g., conduit 202), which is positioned transverseto the patient, or aligned with the incision in the case of anotherincision location or orientation, can be flexible in the bendingdirection. This conformability can be advantageous to provide goodcontact to the wound and periwound region. The conformability may beachieved by a corrugated type of exterior, but a smooth interior. Thesmooth interior channel can be advantageous in some cases for reducinghead losses with the airflow movement. In some embodiments, instead ofcorrugation, the conduit can be bendable in a manner that does not kinkthe channel. The resistance to kinking depends on material selection andthe wall thickness. Thus the conduit may comprise a semi-rigidpolyurethane, a foam, a non-irritating latex, a polystyrene, apolyvinyl, a polyethylene, an ABS, silicone, or other medical gradesemi-rigid material.

The device can be advantageously positioned to sit atop or adjacent tothe wound and body surfaces, contacting the external surfaces of thebody and the incision. The wound care device can protect againstinadvertent puncture, rupture, blunt trauma, sharp trauma, or other harmto the sensitive incision. It can provide compression and binding to themuscle and fascia and skin of the body while allowing for dressingchanges and management of the local wound and periwound environment. Thesupport can have a large window area which is covered by the wounddressing and allows for the transfer and exchange of heat, humidity,gaseous, and liquid matter across the wound and incision site. Thedevice can be open and passive in one iteration, which is a lower-costversion, or it can embody enhanced feedback loops and controllers suchas pumps, valves, humidifier elements, desiccants, and varying geometryof the internal channel, which together work in concert to activelycontrol and modulate the wound healing environment.

Parameters suitable for certain embodiments of the device will now bedescribed.

Temperature: The temperature at the surface interface of the patient andthe conduit lumen can optionally be maintained between 35° C.+/−2° C.The temperature in the conduit lumen can be below body temperature, andas low as 30° C., 25° C., 20° C., or 15° C. in some cases to compensatefor body heat production. In some embodiments, components can beselected for the monitoring of the skin surface near or within thewound—for example thermistors and temperature probes, microcontrollers,resistive heating elements or chemical heating (via controlledexothermic reaction) elements, air flow devices such as diaphragm pumps,piezo pumps, turbine fans, non-bladed fans—and which can create atemperature control feedback loop along the length of the conduit lumen.

Force: the conduit can in some embodiments maintain a lumen that doesnot fully collapse under compression and tension and torsion, impartedby patient's mobility as well as additional mechanical forces impartedby a support component to assist the device's placement and positioningon the body. It may optionally provide levels of compression normal tothe plane of the incision. The compression should optionally beadjustable, rendered by increasing or decreasing the circumferentialforce, for example higher in the first 24 hours of wear and thendecreased over time.

One option of controlling the force of the wrap, e.g., the abdominalbinder may be via an internal array of guidewires or ‘fishing line’,where tension is controlled with a dial. The dial, when turned, eithertakes in line or releases the line, which is stitched into and embeddedin the belt. The increase in tension of the embedded lines in turnincreases or decreases the overall diameter of the belt, or optionallyincreases or decreases certain panels of the belt, increasing ordecreasing the tension and compression forces imparted by the belt ontothe patient wearing the belt.

Humidity: Relative humidity (RH) level in the conduit lumen canoptionally range from about 40%+/−5%, 10%, 15%, or 20%, in order tosupport moisture management at the skin surface.

Moisture: The skin moisture content should optionally be 35%+/−5%,within the temperature range stated above. The minimum (maximumevaporation capability) RH should be able to achieve, in some cases,about 20% at skin content. Moisture can be measured viaconductance/impedance, capacitance, infrared, or other technology.

MVTR: The moisture vapor transmission rate, or evacuation of moistureshould be optionally able to support a transepidermal water loss (TEWL)rate ranging between 5 g/m²/h to 50 g/m²/h. This is the range of ratesof exudate and skin fluid production between normal, high TEWL, andhighly exuding wounds and skin surfaces.

Oxygen Saturation: The oxygen saturation within the conduit lumen canoptionally be no less than 8.5 mol/m³ (approximately equal to oxygencontent of atmospheric air at 30° C.). Maximum oxygen saturation shouldnot, in some embodiments, exceed 20 mol/m³. However, in some embodimentsthe systems and methods can be combined with hyperbaric oxygen therapyto achieve a synergistic result.

Velocity of air: the velocity and volume of air movement is a drivenvalue based on the control parameters for moisture and temperature andhumidity.

The evaporation channel has exposure to the external environment via oneor a multiplicity of portal(s)/hole(s)/vent(s) located optionally at thelateral ends of the channel, or at locations on or along the channel.

The evaporation can be controlled passively through diffusion gradientsbetween the channel and the ambient environment, or optionally,encouraged through a pump or fan mechanism that creates a pressure andvelocity differential to flow air through the channel. In someembodiments, the device can incorporate vacuum/a negative pressuresystem.

Introducing a forced stream or flow of air through the air gap channelincreases the evaporation rate as well as delivers additional oxygen tothe wound and periwound area.

An oxygen-concentrating membrane and oxygen releasing material mayoptionally be incorporated into the air channel. The function of thismembrane or material is to increase the oxygen concentration at thewound site, thereby encouraging healing.

The conduit to the atmosphere may optionally be a single lumen, orcomprised of multiple parallel lumens. However, optionally, the terminusof the lumens may be staggered. The effect of this is that if one end isblocked—due to clothing, patient movement, patient position forexample—then air may flow through an unblocked or unrestricted lumen.

In some embodiments, the device components work together as a system tocreate an air gap/air channel whereby the wound dressing that is againstthe skin and the surrounding absorbent pads, in conjunction with thecompression and fixation wrap or adhesive tabs, combined with thesemi-rigid structure of the conduit that creates the air channel, worktogether to absorb and evaporate wound exudate and periwound moistureaway from the body despite the presence of a panniculus. Because thepanniculus overlies the device, instead of overlaying and occluding thewound site, the bandage therefore is allowed to function more optimallyand the moisture produced by the body from normal or elevatedphysiologic processes (for example wound healing or sweating) is allowedto be absorbed into an aerated bandage which does not become saturatedbecause of the ingress and egress of air flow through the air channels.In some embodiments, the device can stably move, e.g., retract thepanniculus about or at least about 5 mm, 1 cm, 1.5 cm, 2 cm, 2.5 cm, 3cm, 3.5 cm, 4 cm, 4.5 cm, 5 cm, or more away from the wound bed comparedto the location of the panniculus when undisturbed by the device. Thedevice can keep the panniculus in position for at least about 1, 2, 3,4, 5, 6, 7, 8, 12, 16, 24 hours, or more.

The device may optionally function passively; where the feedback loop isnot energized and the evaporation is achieved by the harmoniousintegration of the device elements of the support, the air gapstructure, and the bandage wound dressing.

In some embodiments, the device may function with a feedback loop tomeasure, control and modulate the parameters of the wound healing. Thedevice may optionally contain communication capabilities with anembedded wireless, e.g., Wi-Fi, Bluetooth, or cellular radio chip totransmit certain values from the control loop and send the signal andinformation to a central database or an individual care provider, toallow the remote monitoring of the wound healing status for theindividual wearing the device.

It is contemplated that various combinations or subcombinations of thespecific features and aspects of the embodiments disclosed above may bemade and still fall within one or more of the inventions. Further, thedisclosure herein of any particular feature, aspect, method, property,characteristic, quality, attribute, element, or the like in connectionwith an embodiment can be used in all other embodiments set forthherein. Accordingly, it should be understood that various features andaspects of the disclosed embodiments can be combined with or substitutedfor one another in order to form varying modes of the disclosedinventions. Thus, it is intended that the scope of the presentinventions herein disclosed should not be limited by the particulardisclosed embodiments described above. Moreover, while the invention issusceptible to various modifications, and alternative forms, specificexamples thereof have been shown in the drawings and are hereindescribed in detail. It should be understood, however, that theinvention is not to be limited to the particular forms or methodsdisclosed, but to the contrary, the invention is to cover allmodifications, equivalents, and alternatives falling within the spiritand scope of the various embodiments described and the appended claims.Any methods disclosed herein need not be performed in the order recited.The methods disclosed herein include certain actions taken by apractitioner; however, they can also include any third-party instructionof those actions, either expressly or by implication. For example,actions such as “positioning a wound healing device on a wound site on apatient's abdomen” includes “instructing the positioning of a woundhealing device on a wound site on a patient's abdomen.” The rangesdisclosed herein also encompass any and all overlap, sub-ranges, andcombinations thereof. Language such as “up to,” “at least,” “greaterthan,” “less than,” “between,” and the like includes the number recited.Numbers preceded by a term such as “approximately”, “about”, and“substantially” as used herein include the recited numbers, and alsorepresent an amount close to the stated amount that still performs adesired function or achieves a desired result. For example, the terms“approximately”, “about”, and “substantially” may refer to an amountthat is within less than 10% of, within less than 5% of, within lessthan 1% of, within less than 0.1% of, and within less than 0.01% of thestated amount.

What is claimed is:
 1. A system for improving wound healing, comprising:a wound dressing having a wound-facing surface and a second surface, thewound-facing surface configured to contact a wound of a patient; atleast one conduit having an interior lumen, the conduit operablyconnectable to the second surface of the wound dressing, wherein theconduit comprises a central window configured to allow air flow from theinterior lumen of the conduit to the wound-facing surface of the wounddressing; and a flexible wrap operably connectable to the conduit. 2.The system of claim 1, wherein the window comprises a zone of porousmaterial within the conduit.
 3. The system of claim 1, wherein thewindow comprises apertures within the conduit.
 4. The system of claim 1,wherein the window comprises a cut-out portion of the conduit.
 5. Thesystem of claim 1, wherein the conduit is configured to resistcollapsing upon itself.
 6. The system of claim 1, wherein the conduitcomprises interconnected struts and open cells in between the struts. 7.The system of claim 1, wherein the conduit has a generally circularcross-section.
 8. The system of claim 1, comprising a plurality ofconduits.
 9. The system of claim 1, wherein the conduit comprises acorrugated outer surface.
 10. The system of claim 1, wherein the conduitcomprises removable caps to occlude the lateral ends of the conduit. 11.The system of claim 1, wherein the interior lumen of the conduitcomprises a restriction proximate the central window.
 12. The system ofclaim 1, wherein the flexible wrap comprises a binder configured to wrapcircumferentially around an abdomen of the patient.
 13. The system ofclaim 1, wherein the flexible wrap comprises vertically-orientedadjustable straps.
 14. The system of claim 1, further comprising one ormore sensors operably connected to the conduit, the sensors configuredto measure one or more of: pH, temperature, humidity, air flow velocity,and pressure.
 15. A method for improving wound healing, comprising thesteps of: identifying a patient at risk of wound dehiscence; positioninga wound care system comprising a wound dressing having a skin contactingsurface and a second surface, a conduit having an interior lumenconnected to the second surface of the wound dressing, and a flexiblewrap operably connected to the conduit proximate a wound of thepatient's skin, wherein the wound dressing is positioned substantiallyco-linearly along a long axis of a wound of the patient's skin, whereinthe conduit comprises a window configured to allow air flow from theinterior lumen of the conduit to the wound facing surface of thedressing, and wherein positioning the wound care system stablyrepositions overhanging skin or adipose tissue surrounding the wound toa location farther away from the wound; and securing the wrap around aportion of the patient.
 16. The method of claim 15, wherein the wound isa surgical wound.
 17. The method of claim 16, wherein the surgical woundis an abdominal wound.
 18. The method of claim 17, wherein the abdominalwound is a Caesarean section wound.
 19. The method of claim 15, whereinthe patient has a BMI of greater than about
 30. 20. The method of claim15, wherein the wrap does not occlude the wound after being securedaround a portion of the patient.